sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish red due to iron content; Luster: Dull to Vitreous; Crystal Structure: Microcrystalline/Trigonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58-2.91
- Hardness
- 6
- Color
- Brick red to brownish red due to iron content
- Luster
- Dull to Vitreous
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish red due to iron content; Luster: Dull to Vitreous; Crystal Structure: Microcrystalline/Trigonal; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58-2.91
Formation & geological history
Formed through the infiltration of silica-rich fluids into volcanic ash or fine-grained sedimentary layers, typically during the Precambrian or Paleozoic eras. The red coloration is a result of iron oxidation (rusting) occurring within the silica matrix.
Uses & applications
Commonly used for lapidary work, cabochons, beads, and architectural decoration. In industry, high-silica jasper can be used as a source of quartz or as an abrasive, though it is primarily a decorative jewelry stone.
Geological facts
Jasper has been used as a gemstone since antiquity and is mentioned in the Bible as a stone in the Breastplate of Aaron. Red Jasper is often called the 'Stone of Endurance' in folklore. Some specimens show unique 'brecciated' patterns where the rock has been broken and healed with white quartz veins.
Field identification & locations
Identify in the field by its opaque nature (it does not transmit light even on thin edges), its characteristic conchoidal fracture, and it cannot be scratched by a steel knife. Common in the Western USA, Brazil, South Africa, and India.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary